What does the principle of preexisting obligation imply?

The principle of preexisting obligation refers to the idea that if a party is already legally obligated to perform a certain duty under a contract, they cannot demand additional compensation for fulfilling that same duty. This principle is critical in contract law because it helps prevent unfairness and ensures that parties honor their existing commitments without expecting new benefits for tasks they are already required to perform.

In contexts like contract modifications or renegotiations, this principle maintains that any changes or additional compensation must be based on new considerations or additional duties rather than on obligations that were already agreed upon. As a result, it helps clarify that simply fulfilling a preexisting duty does not warrant additional compensation. Understanding this principle is essential for recognizing how contracts function and ensuring equitable negotiations between parties.